A Médecins Sans Frontières (MSF) worker at an Ebola emergency clinic in Sierra Leone has become a full-time carer to a young girl — literally overnight.

Mush Tiah works the night shift at the MSF clinic in Kailahun, a market town of about 30,000 people at the centre of a region with a population of almost half a million.

The town is near the border with Liberia and Guinea, at the epicentre of West Africa's Ebola epidemic, which has so far killed more than 1,300 people across West Africa.

Now she is the only person left able to care for little Lansanna Kamara, who saw almost all of her family — 17 people in all — die from the Ebola virus.

Ms Tiah told Foreign Correspondent that when Lansanna came to her, she had no clothes and no food.

Her mother died a month ago and was quickly followed by nearly all the remaining members of her family. Lansanna's father survived, but tested positive to the virus and is still being treated in isolation.

Sadly, Lansanna's story is all too common, Ms Tiah said.

Many children at the clinic are younger than 15 and have come because they are either infected themselves or because their parents or relatives are infected or have died.

"Ebola has changed Kailahun," Ms Tiah said. "It's left children alone, some families have all died, many children are not going to school, it's very disheartening."

Going into 'hot zone' as health workers call for reinforcements

Ms Tiah says some people still refuse to believe that Ebola exists.

"But Ebola has come to this country, we all have to accept it, Ebola is here, and it is real," she said.

MSF has said efforts to control the epidemic across four West African states are being undermined by a lack of leadership and emergency management skills that have caused the collapse of health care systems in many places.

It has issued a plea for more outside help, especially experts in tropical medicine and field workers who understand how to help communities prevent the virus from spreading.

Foreign Correspondent gained unprecedented access into Sierra Leone's "hot zone" - the epicentre of the country's outbreak of the deadly haemorrhagic disease. It is here that MSF has set up a crisis coordination centre with help from the International Red Cross and the World Health Organisation.

The crew was the last to enter the district of Kailahun before the area went into lockdown after the Sierra Leone government declared a state of emergency.

Cameraman Adam Bailes travelled with Red Cross worker Patrick Massaquoi on a 12-hour journey from Freetown along dusty roads and stopped along the way at a government hospital in Kenema, where 20 infected nurses had already died.

Here, the International Red Cross is calling for reinforcements of up to 60 clinical and technical staff to help deal with the crisis.

Mr Massaquoi said family and friends were suspicious when he returned from working in the hot zone.

"When I went there for the first time, when I came back, my wife said 'you have to stay far off for 21 days'. I have to really convince her, I have to show her pictures and videos that even though we are involved ... we are highly protected," he said.

Several hours down the road is MSF's Kailahun treatment centre, where Ms Tiah works. The area has virtually no infrastructure, no internet or electricity and little running water.

Concern for local workers 'distressed' by Ebola work

Australian doctor Richard Broome normally works in New South Wales, but has recently returned from Sierra Leone after spending a month assessing the situation for the International Red Cross.

He told Foreign Correspondent that difficult living conditions, combined with aspects of local culture and politics, were fuelling the rapid spread of Ebola in the region.

"People are living in very basic housing with poor access to water, no ability to isolate themselves. Then there are all these cultural issues as well, such as a healthy mistrust of governments, especially in some of these countries that have had very severe civil wars for many years," he said.

"There's a lot of belief in black magic, so people often explain things through witchcraft.

"And all those things come together with the disease and result in the explosive outbreaks."

Dr Broome said the mortality rate from Ebola in Sierra Leone was about 60 per cent. The virus spreads through contact with infected body fluids and overwhelms the immune system, causing organ failure.

At the MSF clinic in Kailahun, those who have tested positive for Ebola are isolated behind plastic webbing, holding water bottles, tins of food and plastic toys that have been thrown to them by workers like Australian MSF psychologist Malcolm Hugo.

He said it is traumatic for locals working with Ebola victims.

"We have about 200 national staff and many of those working with the hygienists have to deal with dead bodies, wash the bodies, prepare the bodies - it can be quite distressing for them not only doing the work, but they can't do it in a traditional culturally sensitive sort of way," Mr Hugo said.

"They often feel quite distressed about what they have to do and a bit stigmatised when they go home."

It is not surprising that healthcare workers are some of those who are most at risk.

Since March, 170 medical workers have contracted Ebola in Guinea, Liberia and Sierra Leone, and 83 have died. MSF workers have also been attacked by angry and worried locals.

Mr Hugo is working to develop a network of foster parents, like Ms Tiah, who can provide short-term care for children until something more permanent can be arranged.

Recovery planning a crucial step in Ebola crisis

At Kenema, another experienced Australian, Amanda McClelland, is at the forefront of the Ebola response.

The International Red Cross's emergency health advisor to Africa and Asia, she said that even though the crisis was still unfolding, recovery planning was crucial.

"Some communities that we've worked with have lost 30 to 40 per cent of their population, some of these places are quite small. How do these communities then undertake agriculture in the future?" she asked.